Journal of general microbiology最新文献_第2页

Glucose utilization and lactate production by Helicobacter pylori. 幽门螺杆菌对葡萄糖的利用和乳酸的产生。

Journal of general microbiology Pub Date : 1993-12-01 DOI: 10.1099/00221287-139-12-3023

G L Mendz, S L Hazell, B P Burns

{"title":"Glucose utilization and lactate production by Helicobacter pylori.","authors":"G L Mendz, S L Hazell, B P Burns","doi":"10.1099/00221287-139-12-3023","DOIUrl":"https://doi.org/10.1099/00221287-139-12-3023","url":null,"abstract":"The transport and incorporation of D-glucose into the human pathogen Helicobacter pylori was investigated employing radioactive tracer analysis and 1H and 13C nuclear magnetic resonance spectroscopy. The bacterium was found to utilize D-glucose contrary to the accepted view that it cannot catabolize carbohydrates. Under the experimental conditions employed, the rate of transport of [14C]glucose was 3.24 mmol min-1 (g protein)-1, and the rate of incorporation into the cellular mass was 1.06 mumol h-1 (g protein)-1. The utilization of [13C]glucose showed biphasic characteristics with a slower initial period followed by a phase with a rate of utilization at least an order of magnitude faster. The apparent rates of decline of glucose levels during both phases varied between strains and depended on the growth conditions of the bacteria prior to harvesting. The main product of glucose catabolism was identified as lactate. These findings provide new perspectives into the physiology of H. pylori and have implications for the active search to develop appropriate therapies for the micro-organism.","PeriodicalId":15884,"journal":{"name":"Journal of general microbiology","volume":"139 12","pages":"3023-8"},"PeriodicalIF":0.0,"publicationDate":"1993-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1099/00221287-139-12-3023","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19119874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 83

Effects of new mutations in the spoIIAB gene of Bacillus subtilis on the regulation of sigma F and sigma G activities. 枯草芽孢杆菌spoIIAB基因新突变对sigma F和sigma G活性调控的影响

Journal of general microbiology Pub Date : 1993-12-01 DOI: 10.1099/00221287-139-12-3197

D Foulger, J Errington

引用次数: 15

Insertion of transposon Tn5 into a structural gene of the membrane-bound nitrate reductase of Thiosphaera pantotropha results in anaerobic overexpression of periplasmic nitrate reductase activity. 将转座子Tn5插入到泛tropha的膜结合硝酸盐还原酶的结构基因中，导致质周硝酸盐还原酶活性的厌氧过表达。

Journal of general microbiology Pub Date : 1993-12-01 DOI: 10.1099/00221287-139-12-3205

L C Bell, M D Page, B C Berks, D J Richardson, S J Ferguson

{"title":"Insertion of transposon Tn5 into a structural gene of the membrane-bound nitrate reductase of Thiosphaera pantotropha results in anaerobic overexpression of periplasmic nitrate reductase activity.","authors":"L C Bell, M D Page, B C Berks, D J Richardson, S J Ferguson","doi":"10.1099/00221287-139-12-3205","DOIUrl":"https://doi.org/10.1099/00221287-139-12-3205","url":null,"abstract":"Chlorate-resistant mutants of the denitrifying bacterium Thiosphaera pantotropha were generated by transposon Tn5 mutagenesis. One class was deficient in membrane-bound nitrate reductase activity but retained a periplasmic nitrate reductase activity. Using transposon marker rescue it was shown that in one such mutant, M-6, the transposon was inserted in the membrane-bound nitrate reductase beta subunit structural gene (termed narH in order to be consistent with the nomenclature of the Escherichia coli major nitrate reductase operon). The translated sequence (total of 106 amino acids) from around the point of transposon insertion showed approximately 90% amino acid identity with the beta subunits of the E. coli nitrate reductases. Under anaerobic growth conditions M-6 overproduced the periplasmic nitrate reductase activity allowing anaerobic growth with nitrate as electron acceptor. A regulatory link was inferred between the presence of the membrane-bound nitrate reductase and expression of the periplasmic nitrate reductase. This is the first demonstration of full denitrification in an organism possessing only a periplasmic nitrate reductase.","PeriodicalId":15884,"journal":{"name":"Journal of general microbiology","volume":"139 12","pages":"3205-14"},"PeriodicalIF":0.0,"publicationDate":"1993-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19117834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 48

Comparison of pathways for biodegradation of monomethyl sulphate in Agrobacterium and Hyphomicrobium species. 农杆菌和菌丝菌生物降解硫酸一甲基途径的比较。

Journal of general microbiology Pub Date : 1993-12-01 DOI: 10.1099/00221287-139-12-2915

T P Higgins, J R Snape, G F White

{"title":"Comparison of pathways for biodegradation of monomethyl sulphate in Agrobacterium and Hyphomicrobium species.","authors":"T P Higgins, J R Snape, G F White","doi":"10.1099/00221287-139-12-2915","DOIUrl":"https://doi.org/10.1099/00221287-139-12-2915","url":null,"abstract":"Different mechanisms have been proposed previously for the biodegradation of monomethyl sulphate (MMS) in Agrobacterium sp. and Hyphomicrobium sp. Sulphate liberation from MMS in Agrobacterium sp. M3C was previously shown to be O2-dependent, whereas in several Hyphomicrobium spp. the initiating step has been considered hitherto to be hydrolytic and catalysed by methyl sulphatase. In the present study, Agrobacterium and Hyphomicrobium strains were compared for their ability to oxidize MMS and its potential metabolites in the oxygen electrode. MMS-grown Agrobacterium sp. M3C and Hyphomicrobium sp. MS223 oxidized MMS with consumption of 0.5 mol O2 per mol of substrate, but they were unable to oxidize methanol. By repeatedly challenging MMS-grown Hypomicrobium with MMS in the electrode chamber, all the O2 in the electrode became exhausted, at which point SO4(2-) liberation stopped although excess MMS was available. SO4(2-) release resumed immediately when O2 was re-admitted to the electrode chamber. Thus liberation of SO4(2-) from MMS in the oxygen electrode was dependent on the continuing availability of O2. Hyphomicrobium sp. MS223 therefore closely resembled Agrobacterium sp. M3C in its obligatory requirement for O2 in MMS degradation. Unlike Agrobacterium sp. M3C, Hyphomicrobium sp. MS223 was able to grow on methanol and methanol-grown cells oxidized methanol (0.5 mol O2 per mol of substrate) but not MMS. Cyclopropanol, an inhibitor of methanol dehydrogenase, abolished oxidation of methanol by methanol-grown Hyphomicrobium sp. MS223 but did not affect oxidation of MMS by MMS-grown cells. Thus Hyphomicrobium sp. MS223 expresses enzymes for oxidation of methanol when needed for growth on this compound, but not when grown on MMS.(ABSTRACT TRUNCATED AT 250 WORDS)","PeriodicalId":15884,"journal":{"name":"Journal of general microbiology","volume":"139 12","pages":"2915-20"},"PeriodicalIF":0.0,"publicationDate":"1993-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19118546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13

Cloning and sequence analysis of the dnaK gene region of Lactococcus lactis subsp. lactis. 乳酸乳球菌亚种dnaK基因区克隆及序列分析。lactis。

Journal of general microbiology Pub Date : 1993-12-01 DOI: 10.1099/00221287-139-12-3253

T Eaton, C Shearman, M Gasson

{"title":"Cloning and sequence analysis of the dnaK gene region of Lactococcus lactis subsp. lactis.","authors":"T Eaton, C Shearman, M Gasson","doi":"10.1099/00221287-139-12-3253","DOIUrl":"https://doi.org/10.1099/00221287-139-12-3253","url":null,"abstract":"A 5.4 kb HindIII fragment of Lactococcus lactis subsp. lactis was identified using a homologous dnaK probe generated by PCR and cloned in Escherichia coli. Upstream sequences were generated by inverse PCR. The two cloned fragments partially overlapped, and sequencing of 5915 bp revealed the presence of four open reading frames in the order orf1-grpE-dnaK-orf4. orf1 encodes a 39 kDa protein of unknown function which shows considerable sequence homology with the Orf39 and Orfa proteins of Bacillus subtilis and Clostridium acetobutylicum, respectively. The downstream ORFs showed high homology to the grpE and dnaK genes of other prokaryotes. The DnaK protein has a characteristic 24-amino-acid deletion exhibited by all the known DnaK proteins of Gram-positive species. In many bacteria the dnaK and dnaJ genes are found as part of the same operon. The L. lactis dnaK operon is unusual in that the dnaK gene is followed by a putative transcription terminator and a fourth large ORF which shares no homology with the dnaJ genes of other bacteria but has a small degree of homology with various membrane proteins. Vegetative promoter sequences are found upstream of both orf1 and orf4. A 12 bp inverted repeat is found upstream of the putative promoter of orf1 and an 8 bp inverted repeat is found between this promoter and the orf1 initiation codon. These repeats are thought to be involved in regulation of the heat-shock genes. The DnaK homologue is induced approximately 3-fold on heat shock at 42 degrees C.","PeriodicalId":15884,"journal":{"name":"Journal of general microbiology","volume":"139 12","pages":"3253-64"},"PeriodicalIF":0.0,"publicationDate":"1993-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1099/00221287-139-12-3253","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19118892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 68

Temperature-sensitive mutation in lytF, a new gene involved in autolysis of Escherichia coli. 参与大肠杆菌自溶的新基因lytF的温度敏感突变。

Journal of general microbiology Pub Date : 1993-12-01 DOI: 10.1099/00221287-139-12-3109

M A Noble, E E Ishiguro

引用次数: 1

Cloning and nucleotide sequence of an extracellular alpha-amylase gene from Aeromonas hydrophila MCC-1. 嗜水气单胞菌mc1胞外α -淀粉酶基因的克隆及核苷酸序列分析。

Journal of general microbiology Pub Date : 1993-12-01 DOI: 10.1099/00221287-139-12-3215

M C Chang, J C Chang, J P Chen

引用次数: 28

Cloning and characterization of a tryptophanase gene from Enterobacter aerogenes SM-18. 产气肠杆菌SM-18色氨酸酶基因的克隆与鉴定。

Journal of general microbiology Pub Date : 1993-12-01 DOI: 10.1099/00221287-139-12-3275

K Kawasaki, A Yokota, S Oita, C Kobayashi, S Yoshikawa, S Kawamoto, S Takao, F Tomita

引用次数: 13

Cloning, mapping and conjugal mobility of pLPG36, a common plasmid from Legionella pneumophila serogroup-1. 嗜肺军团菌血清群-1常见质粒pLPG36的克隆、定位及偶联迁移

Journal of general microbiology Pub Date : 1993-12-01 DOI: 10.1099/00221287-139-12-3171

F López de Felipe

引用次数: 4

The aggregation of human platelets by Lactobacillus species. 乳酸杆菌对人血小板的聚集作用。

Journal of general microbiology Pub Date : 1993-12-01 DOI: 10.1099/00221287-139-12-2945

D W Harty, M Patrikakis, E B Hume, H J Oakey, K W Knox

{"title":"The aggregation of human platelets by Lactobacillus species.","authors":"D W Harty, M Patrikakis, E B Hume, H J Oakey, K W Knox","doi":"10.1099/00221287-139-12-2945","DOIUrl":"https://doi.org/10.1099/00221287-139-12-2945","url":null,"abstract":"The ability to aggregate human platelets was examined for five Lactobacillus rhamnosus strains and five Lactobacillus paracasei subsp. paracasei strains isolated from patients with infective endocarditis (IE), 25 laboratory isolates from the same two species, and 14 strains from five other oral species, namely Lactobacillus acidophilus, Lactobacillus fermentum, Lactobacillus oris, Lactobacillus plantarum and Lactobacillus salivarius. Amongst the L. rhamnosus strains, platelets were aggregated by all five IE strains and 8/16 laboratory strains. For the L. paracasei subsp. paracasei strains, the respective numbers were 2/5 and 2/9. Aggregation also occurred with 11/14 strains of the other five species; each species was represented. The optimal ratio of bacteria to platelets for aggregation was approximately 1:1, and there was considerable variation in the lag phase that preceded aggregation, depending on the source of the platelets. Overall, the lag phase varied between 0.25 +/- 0.1 and 20.4 +/- 3.2 min and the percentage aggregation ranged between 70 +/- 2.6 and 104 +/- 13.5%. Confirmation that aggregation was being observed came from studies with five strains on the inhibitory effects of EDTA, dipyridamole, apyrase, imipramine, acetylsalicylic acid and quinacrine. Inhibition of aggregation by L. rhamnosus strains by the peptide arginine-glycine-aspartic acid-serine (RGDS) further indicated a role for fibronectin and/or fibrinogen. Pronase treatment of cells for 1 h and extraction of bacterial surface components with 0.1 M-Tris/HCl (pH 8.5) at 37 degrees C for 1 h stopped aggregation in 8/9 IE strains. Extracted surface proteins (200 micrograms) completely inhibited platelet aggregation by 8/9 of the homologous strains.(ABSTRACT TRUNCATED AT 250 WORDS)","PeriodicalId":15884,"journal":{"name":"Journal of general microbiology","volume":"139 12","pages":"2945-51"},"PeriodicalIF":0.0,"publicationDate":"1993-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1099/00221287-139-12-2945","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19118548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 51